Closed-end containers



May 22, 1962 D. B. KAuFFx-:LD

CLOSED-END CONTAINERS Filed Feb. l5, 1960' INVENTOR United States Patentlno Filed Feb. 15, 1960, Ser. No. 8,755 8 Claims. (Cl. 229-37) Thisinvention relates to a blank and to a container to be made therefrom,and more particularly relates to an improved end closure structuretherefor.

It is an important object of this invention to provide an improved endclosure which is leakproof, and especially to provide an improved endstructure made from a blank having plastic surfaces, said end structurelending itself to heat-sealing techniques wherein plastic surfaces arewelded as distinguished from glued, although the present structure canbe glued, if desired, or assembled by using any other adhesive.

Another important object of the invention is to provide an improved endclosure for a container made from a laminated blank having a liquidabsorbent core wherein most of the cut edges of the blank are facedoutwardly of the nished container to prevent absorbing of the contentsof the container by the core, known in the art as wicking One side seamof the container, however, faces inwardly and the cut edge thereof istreated with a waterproofing material, i.e. polyethylene sprayed on theedge either before or after the container is set up.

It is another very important object of the invention to provide aninexpensive and easily set-up container and end closure which isespecially adapted for packaging liquids such as milk or other foodproducts since the container and closure structure will meet therequirements of government food packaging regulations. However, thepresent container is also suitable for the packaging of other productssuch as oils, jellies, Syrups, acids, alkalies, detergents, bleaches, orother solid or liquid products either hot, cold or frozen.

Still another major object of the invention is to provide a containerand closure therefor which lies substantially flat to form a rectangularcontainer when the latter is closed and sealed, the end structure havingno recesses to catch and hold foreign matter falling on the sealedcontainer.

A further major object is to provide an end structure especially adaptedto be made from a one-piece die-cut blank which blank is also novel perse, and the end structure being at least double thickness to preventcorner damage if the container is dropped.

Further objects and advantages of the invention will become apparentduring the following discussion of the drawings, wherein:

FIG. l is a plan View of the end portion of a blank according to theinvention, this illustrated portion including part of the length of theside panels, and further including the end closure structure for thecontainer including embossed crease lines shown as dashed lines prior tofolding and seahng the blank, the other end structure of the `blank notbeing illustrated in View of the fact that any suitable closure may beemployed at the other end of the container;

FIG. 2 is a perspective view showing the blank of FIG. l set up toprovide the sidewalls of the body, the end closure flaps being open andlying substantially in the plane ofthe side panels to which they areintegrally attached;

FIG. 3 is a perspective view similar to FIG. l but showing one of theend closure aps partially closed with the ange portions at the edges ofthis ap bent upwardly;

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FIG. 4 is a perspective view similar to FIG. 3 but showing the endclosure iiaps closed to a further extent;

FIG. 5 is a perspective view similar to FIG. 4 but showing the end ofthe container fully closed and sealed;

FIG. 6 is an enlarged cross-sectional view showing a preferredlamination from which the blank and the container shown in the otherfigures may be made; and

FIG. 7 is an enlarged perspective view of one of the corners of theblank shown in FIG. l.

Referring now to FIGS. l and 2, it will be seen that the blank includesfour side panels 21, 31, 41 and 51, these side panels being arrangedside Aby side and mutually separated by four longitudinal embossed bendlines 22, 32, 42 and 52, these bend lines extending the full length ofthe blank. To the right of the bend line 52 is a side seam tab 11, thistab being bent at right angles to the side panel 51 along the `bend line52 and sealed to the inside surface of the leftmost side panel 21, asillustrated in FIG. 2 wherein the blank is set up to form a hollow body.The blank is divided by a transverse embossed crease line which includesthe crease line portions 13, 23, 33, 43 and 53, and which crease lineportions divide the blank into side panels 21, 31, 41 and 51 and endclosure flaps 24, 34, 44 and 54 as well as a tab portion 14 whichhowever is not sealed to the adjacent end flap 24 for reasons which willpresently become apparent. The ap 24 is provided with two diagonalembossed crease lines 25 and 26; the flap 34 is provided with twodiagonal crease lines 35 and 36; and the flap 44 is provided with twodiagonal crease lines 45 and 46. In addition, slits 37 and 3S areprovided in the flap 34 for the purpose hereinafter explained. The tabportion 14 is provided with a diagonal crease line 15, and joins anarrow flange portion 16. Finally, the flap 54 also includes two moreflange portions 47 and 56 joined to the flap 54 at embossed crease lines42 and 57, respectively. As can be seen in FIGS. l and 7, the cornerstructures at the outer ends of ap 54 include diagonal crease lines 58and 59 and small square pieces 61 and 62 separated from the flangeportions by lines which are partly slit and partly embossed.

When the blank is set up as shown in FIG. 2 to form a hollow body ofrectangular cross section, the tab 11 being secured to the side panel21, the next step is to fold the tab 54 along its transverse crease line53 while at the same time folding the upper portion 14 of the taboutwardly along its transverse crease line 13 and its diagonal creaseline 15 While bending the flange portion 16 upwardly, as shown in FIG.3. The triangular tab portion 15', FIG. l, bulges outwardly of thecontainer and extends upwardly to lie adjacent the side of the tabportion 14 and above the plane of the ap 54 as seen in FIG. 4. The tabportion 14 and the ilange 16 lie parallel to and adjacent the flap 24just above its crease line 22, and ilange portions 56 and 47respectively lie against the ilaps 34 and 44, the flange portions 16, 47and 56 then being all sealed to the adjacent flaps in the position shownin FlG. 4. When the sealing of the iiange portions of panel 54 isaccomplished, the cut edges of the flanges face outwardly of thecontainer away from its contents. The small square portions 61 and 62are sealed in the joints in the corners between the flaps and the angeportions and tend to serve as filets to prevent leaking at the corners.

Next, the small triangular member 25', FIG. 1, is bent downwardly aroundthe crease line 25 and over the tab portions 14 and 15 so that it liesparallel with the side ap 24. At this point, it may also be desirable toseal the triangular member 25' against the inside surface of the tab 14so as to make a more liquid-tight corner joint. The flap 44 bendsoutwardly about the crease line 46 so that the triangular portion 46'extends upwardly and lies ilat against the ap 44 and is sealed thereto.

After the flap 54 has been bent inwardly and the flange portions sealedin position as described above and as shown in FIG. 4, the two shorterside flaps 24 and 44 are bent inwardly to overlie the panel 54, while atthe same time the panel 44 is bent along the crease line 45 and thepanel 34 is bent along the crease line 36 so as to provide a triangularweb comprising the panels 45 and 36 as shown in FIG, 4. These twotriangular portions 45' and 36 are squeezed together by the applicationof pressure at the arrows X-X, FIG. 4, these triangular portions fi"Yand 36 being tightly sealed together and the slit 33 permitting thepanel 34 to be warped so that pressure seating means can be applied asshown at the arrows. Likewise, on the other corner which is common tothe end flap 34, a triangular portion 35 and another triangular portion26', the latter being only visible in FIG. l, are squeezed together andsealed, the slit 37 permitting the panel 34 to be warped sufficientlythat a pinching and sealing tool can be applied to the triangularportions 26 and 35. When these triangular portions have all been sealedtogether, the flaps 24 and 44 can then be bent all the way inwardlyaround their respective transverse crease lines 43 and 23 so that theflaps 24 and 44 will lie flat over the top surface of the flap 54, andthe panel 34 at that time will be in partly closed position to overliethe flaps 24, 44 and 54.

The final step is to seal the inside surface of the flap 34 tightly tothe upper surfaces of the flaps 24, 54 and 44 so as to provide areasonably fiat end closure as shown in FIG. 5. If possible, it isdesirable to insert a mandrel inside the open end of the'container bodyand to then tightly compress the flaps together by exerting interior andexterior pressure until a tight seal is secured. This, however, is notconsidered absolutely necessary.

With respect to FIG. 6, this figure illustrates a preferred laminatedmaterial of which the present carton may be made. If the carton is tohold dry material such as birdseed, it could be made of reclaimed Kraftor other paper board and merely glued closed, but the present disclosureseeks to place particular emphasis on a carton structure and onmaterials from which a satisfactory milk carton could be manufactured.In this event, a preferred embodiment of the invention would be made ofvirgin Kraft K coated on both sides with a plastic. This plastic shouldbe a heat-scalable material such as polyethylene P at least on the innersurface, and the outer surface of the container should also be coatedwith a plastic material which may also be polyethylene, or which mayalternatively comprise some other plastic such as vinyl V, it merelybeing necessary that the outer coat V will bond to the polyethylene P ofthe inner coating when heat is applied thereto so that the container maybe heat-sealed by a step closely resembling welding. Any cut edges ofthe laminated blank which face inwardly of the finished container, suchas the edge l1 in FIG. 2, should also he treated by spraying, dipping orotherwise irnpregnating them with the plastic coating material or withsome other easily applied waterproofing material. This disclosure is notto be limited, however, to any particular materials and, as statedabove, it is only necessary that at least one of the plastics be of aweldable type which can be fused at a temperature low enough that theKraft K will not be damaged. It is also contemplated that othermaterials may be added to the laminate for the sake of improving theappearance, rigidity or heat-conductive properties. It is to be notedthat the laminate need not be limited to a core of Kraft.

Referring now to FIG. 4, the first heat-sealing step is carried out justafter closing of the end flap 54, this heat sealing serving to securethe flange portions 16, 47 and 56 to the respective flaps 24, 44 and 34and at the same time securing the tab portion 14 and the triangularportion 2S together and to the inside surface of the side flap 24. Forthis purpose, it is necessary that a clamping and sealing head beapplied around the end of the container so that both heat and pressuremay be applied to the exposed surfaces of the liange portions 16, 47 and56 and the flaps 24, 44 and 34, respectively, just above the transversecrease lines.

rit`he next sealing step is performed at the arrows X-X shown in FIG. 4.The triangular webs 36 and 4S are pinched together and heat is appliedthereto so as to mutually seal the panels and at the same time a similarpressure and heat is applied tothe panels 26 and 35, whereupon the flap34 will be tightly closed against the flaps 2li and which overlie theflap 54. Finally, heat and pressure is applied against the upper surfaceof the flap 34 in the closed position shown in FIG. 5, the pressurebeing preferably opposed by a heated mandrel locat-ed within thecontainer body and abutting the inside surface of the flap 5a.

l do not limit my invention to the exact form shown in the drawings, forobviously changes may be made therein within the scope of the followingclaims.

I claim:

l. A container and end closure made from a single blank and comprisingfour panels and a tab interconnected at four longitudinal bend lines,the blank having a transverse crease line crossing the bend lines atright angles and longitudinally dividing the blank into side panels andend flaps, the tab and one side panel being lapped and sealed togetherto form a hollow body of rectangular cross-section; the first end flapcomprising an inside flap contiguous with a longitudinal portion of saidtab and shaped to close the end of said hollow body and having flangeportions around its periphery; a third end flap located opposite saidfirst fiap and comprising an outside flap shaped to cover the end of thebody; and second and fourth end flaps each of length no greater thansufficient to lie halfway across the end of the body, the second andfourth end flaps both having diagonal crease lines extendingconvergently outwardly from the intersections of the bend lines with thetransverse crease lines, the outer portion of the tab beyond thetransverse crease line having a diagonal crease line extending from theintersection of its transverse crease line with its bend line, said tabportion in the vicinity of its diagonal crease line being foldedoutwardly around said bend line and joining the adjacent flange portionof the first fiap and the latter being folded at right angles around itstransverse crease line to close the end of the body with said fiangeportions parallel with and sealed to adjacent flaps, the triangularportion of the tab between its diagonal crease line and the transversecrease line folding outwardly of the container and being overlapped andsealed to a triangular portion of the adjacent fourth end flap, and lthecorner portion of lthe second flap located between its diagonal creaseline and the adjacent edge of the first flapfolding outwardly of thecontainer and then over the first fiap; the second and fourth flapsbeing folded inwardly at right angles about their transverse creaselines to overlie the first flap, and the triangular portions of thesecond and fourth flaps adjacent the edges of the third flap and definedby respective diagonal crease lines being folded inwardly against thethird flap and the latter then being folded about its transverse line tooverlie the first, second and fourth flaps and being sealed thereto.

2. A container and end closure made from a single blank having surfacesof heat-fusible plastic material and comprising four panels and a tabinterconnected at four longitudinal bend lines, the blank having atransverse crease line crossing the bend lines at right angles andlongitudinally dividing the blank into side panels and end flaps, thetab and one side panel being lapped and heatsealed together to form ahollow body of rectangular cross-section; the first end flap comprisingan inside flap contiguous with a longitudinal portion of said tab andshaped to close the end of said hollow body; and having flange portionsaround its periphery; -a third end flap located opposite said first flapand comprising an outside ap shaped to cover the end of the body; andsecond and fourth end flaps each of length no greater than sutiicient tolie halfway across the end of the body, the second land fourth end flapsboth having diagonal crease lines extending convcrgently outwardly fromthe intersections of the bend lines with the transverse crease lines,and the outer portion of the tab beyond the transverse crease linehaving a diagonal crease line extending from the intersection ofitstransverse crease line with its bend line, said tab portion in thevicinity of its diagonal crease line being folded outwardly around saidbend line and joining the adjacent ange portion of said rst iiap and thelatter being folded at right angles around its transverse crease line toclose the end of the body with said ange portions parallel with -andsealed to adjacent flaps, the triangular portion of the tab between itsdiagonal crease line and the transverse crease line folding outwardly ofthe container and being overlapped and sealed to a triangular portion ofthe adjacent fourth end flap, and the corner portion of the second flaplocated between its diagonal crease line and the adjacent edge of thefirst ap folding outwardly of the container and then `over the firstflap; the second and fourth iiaps being folded inwardly lat right anglesabout their transverse crease lines to overlie the first flap, and thetriangular portions of the second and fourth aps adjacent the edges ofthe third flap and defined by respective diagonal crease lines beingfolded inwardly against the third flap yand heat-sealed thereto and thelatter then being folded about its transverse crease line to overlie thefirst, second and fourth llaps and being heat-sealed thereto.

3. A container and end closure comprising four side panels and alongitudinal tab closed to form a hollow body of rectangular crosssection and divided transversely at a crease line to form four endclosure aps and a tab portion adjacent one side of the first end flap,the latter being shaped to close the end of said body and having angeportions around the periphery, the rst end flap and tab portion beingbent across said end along said transverse crease line and the tabportion having a triangular portion at its crease line bulged outwardlyof the container and said -tab portion and said triangular portion beingsealed to the adjacent end flap; second, third and fourth end flapssealed to the said flange portions, the second and fourth aps being bentat right angles along their crease lines to at least partly overlie saidfirst flap, and said third end flap being located opposite said firstend ap and comprising an outside ap shaped to cover the end of the body,the second and fourth end flaps having triangular corner portions foldedat over the first ap, and the third end ap being bent at right anglesalong its crease line to overlie the first, second and fourth aps andsaid triangular corner portions and sealed thereto.

4. In a container as set forth in claim 3, the second and fourth iiapsbeing of length no greater than half the width of an adjacent flap.

5. In a container as set forth in claim 3, said panels and flapscomprising a single blank having surfaces of heat-fusible plasticmaterial and being thermo-welded together.

6. A one-piece blank for making a container Vand an end closure thereforcomprising four transversely aligned panels and a longitudinal-seamclosing tab respectively defined by four longitudinal embossed bendlines, the blank having a transverse embossed crease line crossing thebend lines at right angles and longitudinally dividing the blank intoside panels and end flaps, the distances from said transverse creaseline to the outer transverse edges of two opposed shorter aps being nogreater than one-half the width of an adjacent panel, and said distanceson the two longer opposed aps substantially equaling the width of anadjacent panel, and one of the longer tiaps having flange portionsaround three of its sides and one of the ange portions joining said tab,and two diagonal embossed crease lines extending in two directions fromeach of the inner corners of both of the shorter flaps outwardly on theflap and on the other one of the longer aps, and a diagonal crease lineextending from one of the inner corners of the first of the longer flapsaway therefrom on said tab portion.

7. In a blank as set forth in claim 6, the lengths of the shorter apsbeing less than one-half the width of an adjacent panel.

8. In a blank as set forth in claim 7, a slit cut into each side of saidsecond of the longer aps in line with the outer transverse edges of theadjacent shorter flaps and each extending partway thereacross lfor adistance approximately equaling the length of the adjacent shorter ap.

References Cited in the file of this patent UNITED STATES PATENTS1,069,021 Miller July 29, 1913 2,403,047 Buttery July 2, 1946 2,439,768Ball Apr. 13, 1948

